The present invention generally relates to awnings and, more specifically, to retractable awnings which include a torsion spring.
There are a number of known retractable awning assemblies which when mounted to a vertical wall create a sheltered area adjacent to the wall. A popular application of such awning assemblies is on the side of a recreational vehicle. The retractable awning assemblies can be divided into two general classes: box-type awnings and shifting-roll-type awnings. Box-type awnings have a rotating roller tube which is mounted to the wall. The awning is unrolled from the tube to an extended position and rolled onto the tube for storage. A box forms a stationary enclosure for the awning when stored. Shifting-roll-type awnings have a rotatable roller tube suspended between two support arms. The tube is moved laterally toward and away from the wall to unroll and roll the awning. One edge of the awning is attached to the wall and the other edge of the awning is attached to the tube. Both types of retractable awnings typically are spring balanced or biased with torsion springs to aid in rolling the awning on the roller tube.
Torsion springs effectively aid in rolling the awning on the roller tube when they have adequate torsion and substantially equal torsion at each end of the roller tube. Prior art methods for applying torsion to the springs, however, has often resulting in uneven or no torsion. The torsion have been typically applied with a hand crank while the operator manually counts the number of turns applied. The operator must physically hold the crank until a locking pin is inserted. This process is not only physically demanding but is also subject to many kinds of errors. For example, the operator can easily miscount the number of turns applied to the roller tube assembly or apply a number of turns intended for a different awning model. This is particularly true when the process is interrupted for a break or at the end of a shift. Accordingly, there is a need in the art for an improved method and apparatus for applying torsion to retractable awning assemblies.